This is a comprehensive Program Project to study the pathogenesis of inflammatory reactions in lung, their mediation and their control. The Program contains four parts. Part I consists of Models of Lung Injury and Inflammation and deals with immune complex induced injury of lung and "targeted" lung injury induced by antibodies to Type II cells, basement membrane and endothelial cells (anti-angiotensin converting enzyme). The role of chemotactic mediators in lung inflammatory reactions and the regulation of these mediators will be assessed. In addition, alveolar cells will be studied for their ability to produce protein inhibitors, internalize protease-inhibitor complexes, and modulate inflammatory reactions in lung. Part II deals with receptors and ultrastructural components of alveolar macrophages, including the role of microtubules and microfilaments in the regulation of alveolar macrophage function. The role of alveolar macrophages in cellular mediated immune reactions also will be studied. Part III deals with prostaglandin biosynthesis by lung tissues, the role of prostaglandins in lung inflammatory reactions, and receptors in pulmonary smooth muscle, together with the effects of prostaglandin inhibitors on these receptors. Part IV consists of CORE, with morphological support for light, transmission and scanning electron microscopy, together with administrative services.